diff options
author | Colin Watson <cjwatson@debian.org> | 2005-03-10 00:24:57 +0000 |
---|---|---|
committer | Colin Watson <cjwatson@debian.org> | 2005-03-10 00:24:57 +0000 |
commit | 5d05471f6657646d1d6500c7c43134462c407ee6 (patch) | |
tree | c142ff8a5b1fcb1c671ba8c6f023746191124d39 /ssh_config.0 | |
parent | 485bab886137bbf8b7ec8df82bd66dc6e5654371 (diff) | |
parent | ebd2ce335af5861020c79fddb1ae35c03bf036cf (diff) |
Import OpenSSH 4.0p1.
Diffstat (limited to 'ssh_config.0')
-rw-r--r-- | ssh_config.0 | 527 |
1 files changed, 527 insertions, 0 deletions
diff --git a/ssh_config.0 b/ssh_config.0 new file mode 100644 index 000000000..9577abc48 --- /dev/null +++ b/ssh_config.0 | |||
@@ -0,0 +1,527 @@ | |||
1 | SSH_CONFIG(5) OpenBSD Programmer's Manual SSH_CONFIG(5) | ||
2 | |||
3 | NAME | ||
4 | ssh_config - OpenSSH SSH client configuration files | ||
5 | |||
6 | SYNOPSIS | ||
7 | $HOME/.ssh/config | ||
8 | /etc/ssh/ssh_config | ||
9 | |||
10 | DESCRIPTION | ||
11 | ssh obtains configuration data from the following sources in the follow- | ||
12 | ing order: | ||
13 | 1. command-line options | ||
14 | 2. user's configuration file ($HOME/.ssh/config) | ||
15 | 3. system-wide configuration file (/etc/ssh/ssh_config) | ||
16 | |||
17 | For each parameter, the first obtained value will be used. The configu- | ||
18 | ration files contain sections separated by ``Host'' specifications, and | ||
19 | that section is only applied for hosts that match one of the patterns | ||
20 | given in the specification. The matched host name is the one given on | ||
21 | the command line. | ||
22 | |||
23 | Since the first obtained value for each parameter is used, more host-spe- | ||
24 | cific declarations should be given near the beginning of the file, and | ||
25 | general defaults at the end. | ||
26 | |||
27 | The configuration file has the following format: | ||
28 | |||
29 | Empty lines and lines starting with `#' are comments. | ||
30 | |||
31 | Otherwise a line is of the format ``keyword arguments''. Configuration | ||
32 | options may be separated by whitespace or optional whitespace and exactly | ||
33 | one `='; the latter format is useful to avoid the need to quote whites- | ||
34 | pace when specifying configuration options using the ssh, scp and sftp -o | ||
35 | option. | ||
36 | |||
37 | The possible keywords and their meanings are as follows (note that key- | ||
38 | words are case-insensitive and arguments are case-sensitive): | ||
39 | |||
40 | Host Restricts the following declarations (up to the next Host key- | ||
41 | word) to be only for those hosts that match one of the patterns | ||
42 | given after the keyword. `*' and `?' can be used as wildcards in | ||
43 | the patterns. A single `*' as a pattern can be used to provide | ||
44 | global defaults for all hosts. The host is the hostname argument | ||
45 | given on the command line (i.e., the name is not converted to a | ||
46 | canonicalized host name before matching). | ||
47 | |||
48 | AddressFamily | ||
49 | Specifies which address family to use when connecting. Valid ar- | ||
50 | guments are ``any'', ``inet'' (use IPv4 only) or ``inet6'' (use | ||
51 | IPv6 only). | ||
52 | |||
53 | BatchMode | ||
54 | If set to ``yes'', passphrase/password querying will be disabled. | ||
55 | This option is useful in scripts and other batch jobs where no | ||
56 | user is present to supply the password. The argument must be | ||
57 | ``yes'' or ``no''. The default is ``no''. | ||
58 | |||
59 | BindAddress | ||
60 | Specify the interface to transmit from on machines with multiple | ||
61 | interfaces or aliased addresses. Note that this option does not | ||
62 | work if UsePrivilegedPort is set to ``yes''. | ||
63 | |||
64 | ChallengeResponseAuthentication | ||
65 | Specifies whether to use challenge response authentication. The | ||
66 | argument to this keyword must be ``yes'' or ``no''. The default | ||
67 | is ``yes''. | ||
68 | |||
69 | CheckHostIP | ||
70 | If this flag is set to ``yes'', ssh will additionally check the | ||
71 | host IP address in the known_hosts file. This allows ssh to de- | ||
72 | tect if a host key changed due to DNS spoofing. If the option is | ||
73 | set to ``no'', the check will not be executed. The default is | ||
74 | ``yes''. | ||
75 | |||
76 | Cipher Specifies the cipher to use for encrypting the session in proto- | ||
77 | col version 1. Currently, ``blowfish'', ``3des'', and ``des'' | ||
78 | are supported. des is only supported in the ssh client for in- | ||
79 | teroperability with legacy protocol 1 implementations that do not | ||
80 | support the 3des cipher. Its use is strongly discouraged due to | ||
81 | cryptographic weaknesses. The default is ``3des''. | ||
82 | |||
83 | Ciphers | ||
84 | Specifies the ciphers allowed for protocol version 2 in order of | ||
85 | preference. Multiple ciphers must be comma-separated. The sup- | ||
86 | ported ciphers are ``3des-cbc'', ``aes128-cbc'', ``aes192-cbc'', | ||
87 | ``aes256-cbc'', ``aes128-ctr'', ``aes192-ctr'', ``aes256-ctr'', | ||
88 | ``arcfour'', ``blowfish-cbc'', and ``cast128-cbc''. The default | ||
89 | is | ||
90 | |||
91 | ``aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour, | ||
92 | aes192-cbc,aes256-cbc'' | ||
93 | |||
94 | ClearAllForwardings | ||
95 | Specifies that all local, remote and dynamic port forwardings | ||
96 | specified in the configuration files or on the command line be | ||
97 | cleared. This option is primarily useful when used from the ssh | ||
98 | command line to clear port forwardings set in configuration | ||
99 | files, and is automatically set by scp(1) and sftp(1). The argu- | ||
100 | ment must be ``yes'' or ``no''. The default is ``no''. | ||
101 | |||
102 | Compression | ||
103 | Specifies whether to use compression. The argument must be | ||
104 | ``yes'' or ``no''. The default is ``no''. | ||
105 | |||
106 | CompressionLevel | ||
107 | Specifies the compression level to use if compression is enabled. | ||
108 | The argument must be an integer from 1 (fast) to 9 (slow, best). | ||
109 | The default level is 6, which is good for most applications. The | ||
110 | meaning of the values is the same as in gzip(1). Note that this | ||
111 | option applies to protocol version 1 only. | ||
112 | |||
113 | ConnectionAttempts | ||
114 | Specifies the number of tries (one per second) to make before ex- | ||
115 | iting. The argument must be an integer. This may be useful in | ||
116 | scripts if the connection sometimes fails. The default is 1. | ||
117 | |||
118 | ConnectTimeout | ||
119 | Specifies the timeout (in seconds) used when connecting to the | ||
120 | ssh server, instead of using the default system TCP timeout. | ||
121 | This value is used only when the target is down or really un- | ||
122 | reachable, not when it refuses the connection. | ||
123 | |||
124 | ControlMaster | ||
125 | Enables the sharing of multiple sessions over a single network | ||
126 | connection. When set to ``yes'' ssh will listen for connections | ||
127 | on a control socket specified using the ControlPath argument. | ||
128 | Additional sessions can connect to this socket using the same | ||
129 | ControlPath with ControlMaster set to ``no'' (the default). | ||
130 | These sessions will reuse the master instance's network connec- | ||
131 | tion rather than initiating new ones. Setting this to ``ask'' | ||
132 | will cause ssh to listen for control connections, but require | ||
133 | confirmation using the SSH_ASKPASS program before they are ac- | ||
134 | cepted (see ssh-add(1) for details). | ||
135 | |||
136 | ControlPath | ||
137 | Specify the path to the control socket used for connection shar- | ||
138 | ing. See ControlMaster above. | ||
139 | |||
140 | DynamicForward | ||
141 | Specifies that a TCP/IP port on the local machine be forwarded | ||
142 | over the secure channel, and the application protocol is then | ||
143 | used to determine where to connect to from the remote machine. | ||
144 | The argument must be a port number. Currently the SOCKS4 and | ||
145 | SOCKS5 protocols are supported, and ssh will act as a SOCKS serv- | ||
146 | er. Multiple forwardings may be specified, and additional for- | ||
147 | wardings can be given on the command line. Only the superuser | ||
148 | can forward privileged ports. | ||
149 | |||
150 | EnableSSHKeysign | ||
151 | Setting this option to ``yes'' in the global client configuration | ||
152 | file /etc/ssh/ssh_config enables the use of the helper program | ||
153 | ssh-keysign(8) during HostbasedAuthentication. The argument must | ||
154 | be ``yes'' or ``no''. The default is ``no''. This option should | ||
155 | be placed in the non-hostspecific section. See ssh-keysign(8) | ||
156 | for more information. | ||
157 | |||
158 | EscapeChar | ||
159 | Sets the escape character (default: `~'). The escape character | ||
160 | can also be set on the command line. The argument should be a | ||
161 | single character, `^' followed by a letter, or ``none'' to dis- | ||
162 | able the escape character entirely (making the connection trans- | ||
163 | parent for binary data). | ||
164 | |||
165 | ForwardAgent | ||
166 | Specifies whether the connection to the authentication agent (if | ||
167 | any) will be forwarded to the remote machine. The argument must | ||
168 | be ``yes'' or ``no''. The default is ``no''. | ||
169 | |||
170 | Agent forwarding should be enabled with caution. Users with the | ||
171 | ability to bypass file permissions on the remote host (for the | ||
172 | agent's Unix-domain socket) can access the local agent through | ||
173 | the forwarded connection. An attacker cannot obtain key material | ||
174 | from the agent, however they can perform operations on the keys | ||
175 | that enable them to authenticate using the identities loaded into | ||
176 | the agent. | ||
177 | |||
178 | ForwardX11 | ||
179 | Specifies whether X11 connections will be automatically redirect- | ||
180 | ed over the secure channel and DISPLAY set. The argument must be | ||
181 | ``yes'' or ``no''. The default is ``no''. | ||
182 | |||
183 | X11 forwarding should be enabled with caution. Users with the | ||
184 | ability to bypass file permissions on the remote host (for the | ||
185 | user's X11 authorization database) can access the local X11 dis- | ||
186 | play through the forwarded connection. An attacker may then be | ||
187 | able to perform activities such as keystroke monitoring if the | ||
188 | ForwardX11Trusted option is also enabled. | ||
189 | |||
190 | ForwardX11Trusted | ||
191 | If this option is set to ``yes'' then remote X11 clients will | ||
192 | have full access to the original X11 display. | ||
193 | |||
194 | If this option is set to ``no'' then remote X11 clients will be | ||
195 | considered untrusted and prevented from stealing or tampering | ||
196 | with data belonging to trusted X11 clients. Furthermore, the | ||
197 | xauth(1) token used for the session will be set to expire after | ||
198 | 20 minutes. Remote clients will be refused access after this | ||
199 | time. | ||
200 | |||
201 | The default is ``no''. | ||
202 | |||
203 | See the X11 SECURITY extension specification for full details on | ||
204 | the restrictions imposed on untrusted clients. | ||
205 | |||
206 | GatewayPorts | ||
207 | Specifies whether remote hosts are allowed to connect to local | ||
208 | forwarded ports. By default, ssh binds local port forwardings to | ||
209 | the loopback address. This prevents other remote hosts from con- | ||
210 | necting to forwarded ports. GatewayPorts can be used to specify | ||
211 | that ssh should bind local port forwardings to the wildcard ad- | ||
212 | dress, thus allowing remote hosts to connect to forwarded ports. | ||
213 | The argument must be ``yes'' or ``no''. The default is ``no''. | ||
214 | |||
215 | GlobalKnownHostsFile | ||
216 | Specifies a file to use for the global host key database instead | ||
217 | of /etc/ssh/ssh_known_hosts. | ||
218 | |||
219 | GSSAPIAuthentication | ||
220 | Specifies whether user authentication based on GSSAPI is allowed. | ||
221 | The default is ``no''. Note that this option applies to protocol | ||
222 | version 2 only. | ||
223 | |||
224 | GSSAPIDelegateCredentials | ||
225 | Forward (delegate) credentials to the server. The default is | ||
226 | ``no''. Note that this option applies to protocol version 2 on- | ||
227 | ly. | ||
228 | |||
229 | HashKnownHosts | ||
230 | Indicates that ssh should hash host names and addresses when they | ||
231 | are added to $HOME/.ssh/known_hosts. These hashed names may be | ||
232 | used normally by ssh and sshd, but they do not reveal identifying | ||
233 | information should the file's contents be disclosed. The default | ||
234 | is ``no''. Note that hashing of names and addresses will not be | ||
235 | retrospectively applied to existing known hosts files, but these | ||
236 | may be manually hashed using ssh-keygen(1). | ||
237 | |||
238 | HostbasedAuthentication | ||
239 | Specifies whether to try rhosts based authentication with public | ||
240 | key authentication. The argument must be ``yes'' or ``no''. The | ||
241 | default is ``no''. This option applies to protocol version 2 on- | ||
242 | ly and is similar to RhostsRSAAuthentication. | ||
243 | |||
244 | HostKeyAlgorithms | ||
245 | Specifies the protocol version 2 host key algorithms that the | ||
246 | client wants to use in order of preference. The default for this | ||
247 | option is: ``ssh-rsa,ssh-dss''. | ||
248 | |||
249 | HostKeyAlias | ||
250 | Specifies an alias that should be used instead of the real host | ||
251 | name when looking up or saving the host key in the host key | ||
252 | database files. This option is useful for tunneling ssh connec- | ||
253 | tions or for multiple servers running on a single host. | ||
254 | |||
255 | HostName | ||
256 | Specifies the real host name to log into. This can be used to | ||
257 | specify nicknames or abbreviations for hosts. Default is the | ||
258 | name given on the command line. Numeric IP addresses are also | ||
259 | permitted (both on the command line and in HostName specifica- | ||
260 | tions). | ||
261 | |||
262 | IdentityFile | ||
263 | Specifies a file from which the user's RSA or DSA authentication | ||
264 | identity is read. The default is $HOME/.ssh/identity for proto- | ||
265 | col version 1, and $HOME/.ssh/id_rsa and $HOME/.ssh/id_dsa for | ||
266 | protocol version 2. Additionally, any identities represented by | ||
267 | the authentication agent will be used for authentication. The | ||
268 | file name may use the tilde syntax to refer to a user's home di- | ||
269 | rectory. It is possible to have multiple identity files speci- | ||
270 | fied in configuration files; all these identities will be tried | ||
271 | in sequence. | ||
272 | |||
273 | IdentitiesOnly | ||
274 | Specifies that ssh should only use the authentication identity | ||
275 | files configured in the ssh_config files, even if the ssh-agent | ||
276 | offers more identities. The argument to this keyword must be | ||
277 | ``yes'' or ``no''. This option is intented for situations where | ||
278 | ssh-agent offers many different identities. The default is | ||
279 | ``no''. | ||
280 | |||
281 | KbdInteractiveDevices | ||
282 | Specifies the list of methods to use in keyboard-interactive au- | ||
283 | thentication. Multiple method names must be comma-separated. | ||
284 | The default is to use the server specified list. | ||
285 | |||
286 | LocalForward | ||
287 | Specifies that a TCP/IP port on the local machine be forwarded | ||
288 | over the secure channel to the specified host and port from the | ||
289 | remote machine. The first argument must be a port number, and | ||
290 | the second must be [bind_address:]host:port. IPv6 addresses can | ||
291 | be specified by enclosing addresses in square brackets or by us- | ||
292 | ing an alternative syntax: [bind_address/]host/port. Multiple | ||
293 | forwardings may be specified, and additional forwardings can be | ||
294 | given on the command line. Only the superuser can forward privi- | ||
295 | leged ports. By default, the local port is bound in accordance | ||
296 | with the GatewayPorts setting. However, an explicit bind_address | ||
297 | may be used to bind the connection to a specific address. The | ||
298 | bind_address of ``localhost'' indicates that the listening port | ||
299 | be bound for local use only, while an empty address or `*' indi- | ||
300 | cates that the port should be available from all interfaces. | ||
301 | |||
302 | LogLevel | ||
303 | Gives the verbosity level that is used when logging messages from | ||
304 | ssh. The possible values are: QUIET, FATAL, ERROR, INFO, VER- | ||
305 | BOSE, DEBUG, DEBUG1, DEBUG2 and DEBUG3. The default is INFO. | ||
306 | DEBUG and DEBUG1 are equivalent. DEBUG2 and DEBUG3 each specify | ||
307 | higher levels of verbose output. | ||
308 | |||
309 | MACs Specifies the MAC (message authentication code) algorithms in or- | ||
310 | der of preference. The MAC algorithm is used in protocol version | ||
311 | 2 for data integrity protection. Multiple algorithms must be | ||
312 | comma-separated. The default is ``hmac-md5,hmac-sha1,hmac- | ||
313 | ripemd160,hmac-sha1-96,hmac-md5-96''. | ||
314 | |||
315 | NoHostAuthenticationForLocalhost | ||
316 | This option can be used if the home directory is shared across | ||
317 | machines. In this case localhost will refer to a different ma- | ||
318 | chine on each of the machines and the user will get many warnings | ||
319 | about changed host keys. However, this option disables host au- | ||
320 | thentication for localhost. The argument to this keyword must be | ||
321 | ``yes'' or ``no''. The default is to check the host key for lo- | ||
322 | calhost. | ||
323 | |||
324 | NumberOfPasswordPrompts | ||
325 | Specifies the number of password prompts before giving up. The | ||
326 | argument to this keyword must be an integer. Default is 3. | ||
327 | |||
328 | PasswordAuthentication | ||
329 | Specifies whether to use password authentication. The argument | ||
330 | to this keyword must be ``yes'' or ``no''. The default is | ||
331 | ``yes''. | ||
332 | |||
333 | Port Specifies the port number to connect on the remote host. Default | ||
334 | is 22. | ||
335 | |||
336 | PreferredAuthentications | ||
337 | Specifies the order in which the client should try protocol 2 au- | ||
338 | thentication methods. This allows a client to prefer one method | ||
339 | (e.g. keyboard-interactive) over another method (e.g. password) | ||
340 | The default for this option is: ``hostbased,publickey,keyboard- | ||
341 | interactive,password''. | ||
342 | |||
343 | Protocol | ||
344 | Specifies the protocol versions ssh should support in order of | ||
345 | preference. The possible values are ``1'' and ``2''. Multiple | ||
346 | versions must be comma-separated. The default is ``2,1''. This | ||
347 | means that ssh tries version 2 and falls back to version 1 if | ||
348 | version 2 is not available. | ||
349 | |||
350 | ProxyCommand | ||
351 | Specifies the command to use to connect to the server. The com- | ||
352 | mand string extends to the end of the line, and is executed with | ||
353 | /bin/sh. In the command string, `%h' will be substituted by the | ||
354 | host name to connect and `%p' by the port. The command can be | ||
355 | basically anything, and should read from its standard input and | ||
356 | write to its standard output. It should eventually connect an | ||
357 | sshd(8) server running on some machine, or execute sshd -i some- | ||
358 | where. Host key management will be done using the HostName of | ||
359 | the host being connected (defaulting to the name typed by the us- | ||
360 | er). Setting the command to ``none'' disables this option en- | ||
361 | tirely. Note that CheckHostIP is not available for connects with | ||
362 | a proxy command. | ||
363 | |||
364 | PubkeyAuthentication | ||
365 | Specifies whether to try public key authentication. The argument | ||
366 | to this keyword must be ``yes'' or ``no''. The default is | ||
367 | ``yes''. This option applies to protocol version 2 only. | ||
368 | |||
369 | RemoteForward | ||
370 | Specifies that a TCP/IP port on the remote machine be forwarded | ||
371 | over the secure channel to the specified host and port from the | ||
372 | local machine. The first argument must be a port number, and the | ||
373 | second must be [bind_address:]host:port. IPv6 addresses can be | ||
374 | specified by enclosing any addresses in square brackets or by us- | ||
375 | ing the alternative syntax: [bind_address/]host/port. Multiple | ||
376 | forwardings may be specified, and additional forwardings can be | ||
377 | given on the command line. Only the superuser can forward privi- | ||
378 | leged ports. | ||
379 | |||
380 | If the bind_address is not specified, the default is to only bind | ||
381 | to loopback addresses. If the bind_address is `*' or an empty | ||
382 | string, then the forwarding is requested to listen on all inter- | ||
383 | faces. Specifying a remote bind_address will only succeed if the | ||
384 | server's GatewayPorts option is enabled (see sshd_config(5)). | ||
385 | |||
386 | RhostsRSAAuthentication | ||
387 | Specifies whether to try rhosts based authentication with RSA | ||
388 | host authentication. The argument must be ``yes'' or ``no''. | ||
389 | The default is ``no''. This option applies to protocol version 1 | ||
390 | only and requires ssh to be setuid root. | ||
391 | |||
392 | RSAAuthentication | ||
393 | Specifies whether to try RSA authentication. The argument to | ||
394 | this keyword must be ``yes'' or ``no''. RSA authentication will | ||
395 | only be attempted if the identity file exists, or an authentica- | ||
396 | tion agent is running. The default is ``yes''. Note that this | ||
397 | option applies to protocol version 1 only. | ||
398 | |||
399 | SendEnv | ||
400 | Specifies what variables from the local environ(7) should be sent | ||
401 | to the server. Note that environment passing is only supported | ||
402 | for protocol 2, the server must also support it, and the server | ||
403 | must be configured to accept these environment variables. Refer | ||
404 | to AcceptEnv in sshd_config(5) for how to configure the server. | ||
405 | Variables are specified by name, which may contain the wildcard | ||
406 | characters `*' and `?'. Multiple environment variables may be | ||
407 | separated by whitespace or spread across multiple SendEnv direc- | ||
408 | tives. The default is not to send any environment variables. | ||
409 | |||
410 | ServerAliveInterval | ||
411 | Sets a timeout interval in seconds after which if no data has | ||
412 | been received from the server, ssh will send a message through | ||
413 | the encrypted channel to request a response from the server. The | ||
414 | default is 0, indicating that these messages will not be sent to | ||
415 | the server. This option applies to protocol version 2 only. | ||
416 | |||
417 | ServerAliveCountMax | ||
418 | Sets the number of server alive messages (see above) which may be | ||
419 | sent without ssh receiving any messages back from the server. If | ||
420 | this threshold is reached while server alive messages are being | ||
421 | sent, ssh will disconnect from the server, terminating the ses- | ||
422 | sion. It is important to note that the use of server alive mes- | ||
423 | sages is very different from TCPKeepAlive (below). The server | ||
424 | alive messages are sent through the encrypted channel and there- | ||
425 | fore will not be spoofable. The TCP keepalive option enabled by | ||
426 | TCPKeepAlive is spoofable. The server alive mechanism is valu- | ||
427 | able when the client or server depend on knowing when a connec- | ||
428 | tion has become inactive. | ||
429 | |||
430 | The default value is 3. If, for example, ServerAliveInterval | ||
431 | (above) is set to 15, and ServerAliveCountMax is left at the de- | ||
432 | fault, if the server becomes unresponsive ssh will disconnect af- | ||
433 | ter approximately 45 seconds. | ||
434 | |||
435 | SmartcardDevice | ||
436 | Specifies which smartcard device to use. The argument to this | ||
437 | keyword is the device ssh should use to communicate with a smart- | ||
438 | card used for storing the user's private RSA key. By default, no | ||
439 | device is specified and smartcard support is not activated. | ||
440 | |||
441 | StrictHostKeyChecking | ||
442 | If this flag is set to ``yes'', ssh will never automatically add | ||
443 | host keys to the $HOME/.ssh/known_hosts file, and refuses to con- | ||
444 | nect to hosts whose host key has changed. This provides maximum | ||
445 | protection against trojan horse attacks, however, can be annoying | ||
446 | when the /etc/ssh/ssh_known_hosts file is poorly maintained, or | ||
447 | connections to new hosts are frequently made. This option forces | ||
448 | the user to manually add all new hosts. If this flag is set to | ||
449 | ``no'', ssh will automatically add new host keys to the user | ||
450 | known hosts files. If this flag is set to ``ask'', new host keys | ||
451 | will be added to the user known host files only after the user | ||
452 | has confirmed that is what they really want to do, and ssh will | ||
453 | refuse to connect to hosts whose host key has changed. The host | ||
454 | keys of known hosts will be verified automatically in all cases. | ||
455 | The argument must be ``yes'', ``no'' or ``ask''. The default is | ||
456 | ``ask''. | ||
457 | |||
458 | TCPKeepAlive | ||
459 | Specifies whether the system should send TCP keepalive messages | ||
460 | to the other side. If they are sent, death of the connection or | ||
461 | crash of one of the machines will be properly noticed. However, | ||
462 | this means that connections will die if the route is down tem- | ||
463 | porarily, and some people find it annoying. | ||
464 | |||
465 | The default is ``yes'' (to send TCP keepalive messages), and the | ||
466 | client will notice if the network goes down or the remote host | ||
467 | dies. This is important in scripts, and many users want it too. | ||
468 | |||
469 | To disable TCP keepalive messages, the value should be set to | ||
470 | ``no''. | ||
471 | |||
472 | UsePrivilegedPort | ||
473 | Specifies whether to use a privileged port for outgoing connec- | ||
474 | tions. The argument must be ``yes'' or ``no''. The default is | ||
475 | ``no''. If set to ``yes'' ssh must be setuid root. Note that | ||
476 | this option must be set to ``yes'' for RhostsRSAAuthentication | ||
477 | with older servers. | ||
478 | |||
479 | User Specifies the user to log in as. This can be useful when a dif- | ||
480 | ferent user name is used on different machines. This saves the | ||
481 | trouble of having to remember to give the user name on the com- | ||
482 | mand line. | ||
483 | |||
484 | UserKnownHostsFile | ||
485 | Specifies a file to use for the user host key database instead of | ||
486 | $HOME/.ssh/known_hosts. | ||
487 | |||
488 | VerifyHostKeyDNS | ||
489 | Specifies whether to verify the remote key using DNS and SSHFP | ||
490 | resource records. If this option is set to ``yes'', the client | ||
491 | will implicitly trust keys that match a secure fingerprint from | ||
492 | DNS. Insecure fingerprints will be handled as if this option was | ||
493 | set to ``ask''. If this option is set to ``ask'', information on | ||
494 | fingerprint match will be displayed, but the user will still need | ||
495 | to confirm new host keys according to the StrictHostKeyChecking | ||
496 | option. The argument must be ``yes'', ``no'' or ``ask''. The | ||
497 | default is ``no''. Note that this option applies to protocol | ||
498 | version 2 only. | ||
499 | |||
500 | XAuthLocation | ||
501 | Specifies the full pathname of the xauth(1) program. The default | ||
502 | is /usr/X11R6/bin/xauth. | ||
503 | |||
504 | FILES | ||
505 | $HOME/.ssh/config | ||
506 | This is the per-user configuration file. The format of this file | ||
507 | is described above. This file is used by the ssh client. Be- | ||
508 | cause of the potential for abuse, this file must have strict per- | ||
509 | missions: read/write for the user, and not accessible by others. | ||
510 | |||
511 | /etc/ssh/ssh_config | ||
512 | Systemwide configuration file. This file provides defaults for | ||
513 | those values that are not specified in the user's configuration | ||
514 | file, and for those users who do not have a configuration file. | ||
515 | This file must be world-readable. | ||
516 | |||
517 | SEE ALSO | ||
518 | ssh(1) | ||
519 | |||
520 | AUTHORS | ||
521 | OpenSSH is a derivative of the original and free ssh 1.2.12 release by | ||
522 | Tatu Ylonen. Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo | ||
523 | de Raadt and Dug Song removed many bugs, re-added newer features and cre- | ||
524 | ated OpenSSH. Markus Friedl contributed the support for SSH protocol | ||
525 | versions 1.5 and 2.0. | ||
526 | |||
527 | OpenBSD 3.6 September 25, 1999 8 | ||